The following paper shows some of the changes that IPv6 has introduced to meet the requirements of the "mobile Internet" and how it will be possible for eavesdroppers in the network to identify packets that belong to a particular node and track its movements. Three proposals that try to prevent this kind of location information leakage are presented within the level of privacy achieved. The first one deals with stateless address autoconfiguration and the generation of random interface identifiers; the second tries to hide the home address of the mobile node from third parties using a temporary mobile identifier and the last one uses hierarchical MobileIPv6 basic mode to hide the link care of address to correspondent nodes by using the regional care-of-address. The main contribution of the author in this paper is the concept of unobservable pseudo random interface identifier which enhances the privacy extension for stateless address autoconfiguration.